was a group of students that had traveled from florida, i believe they drove overnight to get up to sandy hook, and they appeared at the memorial site and just started playing and singing. ♪ >> i understand you're grieving. we are here for you. >>> investigating today did a new sweep of the house where adam lanza and his mother lived. we asked the police chief what he found. what was lanza's state at the time of the shooting. we look at autism and killer's brains as we continue to focus on mental health. >>> and tonight, no deal in washington. let's go "outfront." >>> good evening, everyone. "outfront" tonight, desperate for answers. investigators spent the day at the home of 20-year-old adam lanza, sweeping the house for evidence of a motive. behind the rampage in which 20 children were killed and seven adults, including his own mother. there are also new details tonight about nancy lanza's whereabouts in the days before the shooting. deborah fayerick is live outside the home tonight. what has happened there tonight and today? >> it's rather remarkable because the major crime squad has